Improvement in sheaves



dished grates patent dtjiliire.

Letters Patent N 106,335, dated August 16, 1870.

IMPROVEMENT IN SHEAVES.

The Schedule referred to in these Lettera Patent and making part of the same I, HILAS D. DAVIS, of North Audover, in the county of Essex andState of Massachusetts, have invented an improved Sheave, of which the following is a specification.

Nature and Object of the Invention.

My invention relates to the method'of constructing the sheaves which are used in mountingheddles in looms, so thatthey may he n'rade. of sufficient strength, and yet much lighter and also cheaper than those in common use.

The sheaves usually employed in mounting heddles are made of cast-iron, and are, necessarily, when made as light as practicable, of considerable weight; and in mounting a looin with, say, twenty leaves of heddles with six sheaves (three above and three bclow)to each leaf, there would" be required one hundred and twenty sheaves in all, and as 'these have to bepartially, rotated with a reciprocating motion at each movement of the warps, their united inertia and momentum in stopping and starting at each pick, ofl'ers considerable resistance to the easy working of the loom, and consuniesa considerable amount of the power without any corresponding useful result, and especially in operating the loom rapidly. Bl1ii" by constructing the sheaves of 'tin, or other sheet-metal, in the manner herein described, they can bemade of a better form, and of much less weight and cost, and less liable to be broken,-than when made of cast-iron.

Although this mode of making sheaves was especially designed for mounting heddles, it is equally applicable to any other purpose to which its qualities adapt it.

Description.-

In the drawing- Figure 1 is a side elevation ot'.a sheave, full size; and

Figure 2 is a section of the saine,-showing one form of inserting the bushing orhub to receive the hole at the center.

Figures 3 and 4 are an elevation and section, showing another mode of applying the central bushing 01' hub, so that it maybe removed. 7

The sheave is formed of two pieces of tin plate, A, which are struckJup to form in a die by the wellknown process of making raised work, which pieces are placed together face to face, and united bya bushing or hub, B, which is insertedin the central hole and secured therein by soldering, as is shown in figs;

1 and 2, or by flanges upon the bushing, as is shown in figs. 3 and 4, the flangeG being formed upon the bushing, and the flange I) screwed upon the same, so as to clamp the plates between them. I

In this last case, the plates would not bebent out at a right angleat the central hole, as is shown at E, fig. 2.

The plates may also be, united by a line of solder at H, around the circumference, if desired.

F F are holes in the flange 1),'t-0 receive a wrench or spanner to screw it up.

By this means asheave can be made of a less thickness than in any other practicable way known to me, and yet give a suflicient depth and breadth to the groove G for the cord, without liability of its being broken, which is a matter of great importance in using a large number of heddles, where it is very desirable to make them as thin as possible.

\Vhat I claim as my invention, is-

A sheave formed of two thin plates of metal, enibossed to form, and placed together face to face, and combined with a central bushing or hub, substantially as described.

Executed March 23, 1870. v

HILAS I). DAVIS.

Witnesses G. E. WHITNEY, WM. 0. HIBBARD. 

